[MPlayer-dev-eng] Re: [PATCH] real muting

[Alban Bedel]

On Sun, 20 Nov 2005 11:17:30 +0100
Reimar Döffinger <Reimar.Doeffinger at stud.uni-karlsruhe.de> wrote:

> Hi,
> the attached patch implements real muting (i.e. the audio device gets
> paused).

Having a real muting (when available at the driver/hw level) is a good
idea, but pausing the ao to simulate this seems like a really bad idea
to me.

> It currently disables the "set volume to 0" part, too, this probably
> should be an option (suggestions for name + values?).
>
> Please test it, I'm sure it will cause problems in some cases, e.g.
> with -ao alsa the movie makes a short skip forward when muting.

The video is synched on the soundcard, so this method is just asking for
troubles. Some ao will keep their buffer when pausing, so the sound
migth restart with a rest of what was played before, then brutaly jump
to a completly different signal, which may very well produce bad
artifacts. If the ao drop the buffer, then it have to be refilled leading
to some jump in the video. All in all I bet this will work smoothly
(ie like now) in perhaps 1% of the cases.

Why not just add a control() to the ao and implement it there ? That way
ao that have a real muting (like alsa) could use it, other would just
fallback on the current implementation and set the volume to 0 which
is more than good enouth in 99% of the cases.

	Albeu